Boehringer Ingelheim has formed a non-exclusive collaboration with Presidio Pharmaceuticals to examine three direct-acting antivirals in combination in a Phase IIa trial in patients with chronic hepatitis C virus (HCV) infection. The trial will evaluate Presidio’s pan-genotypic NS5A inhibitor PPI-668, which has completed Phase I studies, with Boehringer Ingelheim’s Phase III protease inhibitor faldaprevir (BI201335) and its non-nucleoside polymerase inhibitor BI207127, with or without ribavirin in patients with HCV genotype-1a infection. The two companies will continue to retain rights to their respective compounds.